This content is only for readers outside of the US as it discusses a device that is not FDA approved.
The ACURATE neo (Boston Scientific) is a transcatheter aortic valve implantation (TAVI) device made of a self-expanding nitinol frame and porcine pericardial leaflets in a supra-annular position. Data not only indicate that it is a safe and effective device, but also show that it may be especially beneficial in patients with reduced left ventricular function and/or a small aortic annulus.
According to Christian Hengstenberg (Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria), ACURATE neo is a “very safe device”. He comments that with the valve, “you have very high rates of implantation success and a low pacemaker rate”. “Everything looks nice with this device,” Hengstenberg adds.
Data from the SAVI-TF registry support his assertion that the device is safe and effective.1 In EuroIntervention, Helge Möllmann (Department of Cardiology, Kerckhoff Heart and Lung Center, Bad Nauheim, Germany) and colleagues report the outcomes of 1,000 patients who underwent TAVI with the ACURATE neo in the SAVI-TF registry. They state that at 30 days, the rate of all-cause mortality (the primary endpoint) was 1.4% and that the early safety composite occurred in 8.6% of patients (disabling stroke was 1.2% and permanent pacemaker implantation was 8.3%). “New York Heart Association (NYHA) Class improved significantly from baseline with 90% of patients in NYHA Class I or II at 30 days,” they add.
Möllmann et al observed that the rate of permanent pacemaker implantation seen in their registry was lower than that seen with other devices, noting that CoreValve Evolut R (Medtronic) is associated with a permanent pacemaker rate of 22.1%. Additionally, they comment that its “very low pacemaker rate” might make ACURATE neo “particularly useful for patients with reduced left ventricular ejection fraction”.
Hengstenberg, who was one of the investigators in the SAVI-TF registry, suggests that the mechanism of release of ACURATE neo may explain why it appears to have a lower pacemaker rate than other devices. He comments: “Other self-expanding valves have a ‘bottom-up’ release mechanism. Therefore, you start in the left ventricle and this may irritate the conduction system—you have to remember that you are in a beating heart, so there will always be a little bit of motion and movement. With ACURATE neo, you have a ‘top-down’ mechanism of release; so, you deploy first the upper part in the aortic valve and only then in the lower part in the subannular area. I think this is, therefore, less of an irritant to the conduction system.”
Avoiding the need for a permanent pacemaker, according to Hengstenberg, is an important consideration. He explains that implanting a permanent pacemaker not only prolongs the hospital stay and increases the cost of the procedure, but also is a “negative influence” on patient outcomes.
Two ongoing randomised controlled trials—SCOPE 1 and SCOPE 2—are evaluating how ACURATE neo compares with existing devices (Edward Lifesciences’ SAPIEN 3 and Medtronic’s Corevalve family, respectively). However, in the meantime, propensity-matched studies have provided some insight into how the device fares in comparison to Edwards’ SAPIEN 3.
Victor Mauri (Departments of Cardiology, Heart Center, University of Cologne, Germany) and colleagues performed a multicentre, propensity-matched comparison between ACURATE neo and SAPIEN 3 in patients with a small aortic annulus (<400mm2) who were undergoing TAVI.2 After identifying 92 matched patients (from 246 patients overall), they found that the 30-day rates of death, stroke, vascular complication, and bleeding were all similar between both groups.
However, mean transvalvular gradients were significantly lower in the ACURATE neo group: 9.3±3.9mmHg vs. 14.5±5.5mmHg for SAPIEN 3 (p<0.001). This meant that the effective orifice area was significantly larger with ACURATE neo (0.96±0.3cm2/m2 vs. 0.8±0.2cm2/m2 for SAPIEN 3 patients; p=0.002). “Consequently, prosthesis-patient mismatch occurred significantly more often in the SAPIEN 3 group (41% for ACURATE neo vs. 67% for SAPIEN 3; p=0.002) and was classified as severe in 3% of ACURATE neo patients and in 22% of SAPIEN 3 patients (p=0.004),” the authors report.
ACURATE neo is a supra-annular valve rather than an intra-annular valve, and this may explain why it is associated with a lower rate of prosthesis-patient mismatch. Hengstenberg comments: “SAPIEN 3 is an intra-aortic valve, meaning the main valve is exactly the height of the annulus; ACURATE neo is a supra-annular valve, so the valve is above the annulus. If you have a small annulus to start with [as in Mauri et al’s study] and you put in an intra-annular valve in there, you always end up with a higher gradient.” He adds that higher gradient rates—associated with prosthesis-patient mismatch—are “often linked to a less favourable outcome for the patient”. Mauri et al, in their conclusion, comment: “Whether prosthesis-patient mismatch after TAVI translates into decreased prosthesis durability and impaired long-term outcomes remains to be elucidated. However, the results emphasise the need of careful prosthesis selection in each individual patient.”
In a second multicentre study comparing ACURATE neo with SAPIEN 3 in a propensity-matched analysis,3 data showed comparable safety and efficacy results for both valves with similar rates of all-cause mortality at 30 days. However, ACURATE neo, was associated with significantly lower rates for permanent pacemaker implantation and elevated gradients; the rate of paravalvular leak was higher with ACURATE neo. Study investigators Oliver Husser (Technical University Munich, Munich, Germany) and colleagues report: “In a propensity-matched comparison, we found equivalent rates of devices failure and the early safety composite endpoint with ACURATE neo and SAPIEN 3.”
Summarising the available data for ACURATE neo, Hengstenberg comments that the valve is an “all comers” valve that “is capable of providing extremely good results in almost all patients”. Additionally, he notes: “If there is severe calcification expanding into the left ventricular outflow tract, we know that the risk for annulus rupture is very high with balloon-expandable valves. Also, a horizontal position of the heart is sometimes very hard to treat, but not with the ACURATE neo valve, which is able to self-adjust its position.”
- ACURATE neo transcatheter aortic valve system demonstrates excellent clinical outcomes and very low complication rates in 1,000 patients’ international, all-comers SAVI-TF registry (Möllmann et al).
- Compared with SAPIEN 3, ACURATE neo shows comparable safety and efficacy endpoints and is associated with lower transvalvular gradients and, consequently, less prosthesis–patient mismatch in patients with small annulus (Mauri et al).
- There are fewer new pacemaker implantations and fewer elevated gradients with ACURATE neo than there are with SAPIEN 3 (Husser et al).
- Möllmann H, Hengstenberg C, Hilker M, et al. Real-world experience using the ACURATE neo prosthesis: 30-day outcomes of 1,000 patients enrolled in the SAVI-TF registry. EuroIntervention 2017. Epub.
- Mauri V, Kim WK, Abumayyaleh M, et al. Short-term outcome and hemodynamic performance of next-generation self-expanding versus balloon-expandable transcatheter aortic valves in patients with small aortic annulus: A multicenter propensity-matched comparison. Circ Cardiovasc Interv 2017. Epub.
- Husser O, Kim WK, Pellegrini C. Multicenter comparison of novel self-expanding versus balloon-expandable transcatheter heart valves. JACC: Cardiovascular Interventions 2017; 10: 2078–87
This article has been sponsored by Boston Scientific.